Stratolaunch has yet to send its first payload into orbit, but the company announced today that it is developing a new family of air-launched boosters that will enter service in 2020. The four rockets of various sizes will be carried by the world's largest aircraft, the dual-fuselage Stratolaunch, which has wingspan of 385 ft (117 m) and will be able to carry a range of payloads into multiple orbits and inclinations in a single launch mission.

Stratolaunch has been under development since 2011 with the goal of developing a private commercial air-launch vehicle capable of sending relatively small payloads into a variety of Earth orbits. Until now, the company has concentrated on the Pegasus rocket, which was originally developed by Orbital ATK (now part of Northrop Grumman) and first flew in the early 1990s.

According to Stratolaunch, the Pegasus has managed more than 35 successful launches, though not yet with the Stratolaunch aircraft, which can launch three of the rockets per flight. The Pegasus can carry a payload of 816 lb (370 kg) in to a 250 mi (400 km) orbit and is currently undergoing integration and testing in the run up to the first flight in 2020.

The new rockets that will join the Pegasus include a Medium Launch Vehicle (MLV) that can handle a 7,500 lb (3,400 kg payload) and is slated to fly in 2022. A Heavy variant of the MLV is also under development that can lift 13,000 lb (6,000 kg) into low-Earth orbit using two side boosters.

The fourth launcher is a Space Plane – a fully-reusable winged launcher that can carry both medium payloads and astronauts into orbit, though this is currently in the design study phase.

"We are excited to share for the first time some details about the development of our own, proprietary Stratolaunch launch vehicles, with which we will offer a flexible launch capability unlike any other," says Jean Floyd, Chief Executive Officer at Stratolaunch. "Whatever the payload, whatever the orbit, getting your satellite into space will soon be as easy as booking an airline flight."

Source: Stratolaunch